Gotthard Base Tunnel work continues in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km (35.4 miles) through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016.

Gotthard Base Tunnel work continues in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km (35.4 miles) through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km (35.4 miles) through the Swiss Alps, making it the longest railway tunnel in the ... more

A giant drilling machine completes the world's longest tunnel beneath the Swiss Alps during a ceremony on October 15, 2010, 30 kilometres (19 miles) from one end and 2,000 metres below the mountains near Sedrun. By the time it opens for service in 2017, the 57-kilometre (35.4-mile) long Gotthard tunnel, it will exceed Seikan rail tunnel linking the Japanese islands of Honshu and Hokkaido and the world's longest road tunnel of Laerdal in Norway, paving the way for continuous high-speed rail travel between northern and southeastern Europe. less

A giant drilling machine completes the world's longest tunnel beneath the Swiss Alps during a ceremony on October 15, 2010, 30 kilometres (19 miles) from one end and 2,000 metres below the mountains near ... more

Miners prepare a stone wall for detonation at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

Miners prepare a stone wall for detonation at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link ... more

Miners prepare a stone wall for detonation at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

Miners prepare a stone wall for detonation at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link ... more

Interior view of the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

Interior view of the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At ... more

Photo: Johannes Simon, Getty Images

Interior view of the construction site for the Gotthard Base Tunnel... Photo-8566812.116216 - Houston Chronicle

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Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Caterpillars are operate inside the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. The completion is planned for 2018. less

Caterpillars are operate inside the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich ... more

Photo: Johannes Simon, Getty Images

Caterpillars are operate inside the construction site for the... Photo-8566823.116216 - Houston Chronicle

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A giant drill removes Alpine rocks at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

A giant drill removes Alpine rocks at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between ... more

Photo: Johannes Simon, Getty Images

A giant drill removes Alpine rocks at the construction site for the... Photo-8566818.116216 - Houston Chronicle

Image 12 of 44

A miner waters the floor at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240 kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

A miner waters the floor at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and ... more

Photo: Johannes Simon, Getty Images

A miner waters the floor at the construction site for the Gotthard... Photo-8566824.116216 - Houston Chronicle

Image 13 of 44

Miners prepare a stone wall for detonation at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

Miners prepare a stone wall for detonation at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link ... more

A miner handles explosives at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich and Milan. At 57 kilometres (35 miles) The Gotthard Base Tunnel will be the world's longest tunnel. A key feature of the project, which is new to alpine transport, is the fact that the entire railway line will stay at the same altitude of 500 metres (1,650ft) above sea level. This will allow trains using the line to reach speeds of 240kmh (149mph), reducing the travel time between Zurich and Milan from today's four hours to just two-and-a-half. less

A miner handles explosives at the construction site for the Gotthard Base Tunnel on April 19, 2007 near Sedrun, Switzerland. Deep beneath the Alps, the Swiss are building a high-speed rail link between Zurich ... more

Photo: Johannes Simon, Getty Images

A miner handles explosives at the construction site for the... Photo-8566821.116216 - Houston Chronicle

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Taboola Gallery Frame Item-85307.116216 - Houston Chronicle

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A giant drilling machine completes the world's longest tunnel beneath the Swiss Alps during a ceremony on October 15, 2010, 30 kilometres (19 miles) from one end and 2,000 metres below the mountains near Sedrun. By the time it opens for service in 2017, the 57-kilometre (35.4-mile) long Gotthard tunnel will exceed Seikan rail tunnel linking the Japanese islands of Honshu and Hokkaido and the world's longest road tunnel of Laerdal in Norway, paving the way for continuous high-speed rail travel between northern and southeastern Europe. less

A giant drilling machine completes the world's longest tunnel beneath the Swiss Alps during a ceremony on October 15, 2010, 30 kilometres (19 miles) from one end and 2,000 metres below the mountains near ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Workers celebrate the break trough of the second shaft of Gotthard Tunnel on October 15, 2010 in Sedrun, Switzerland. The world's longest tunnel, which has been under construction for 14 years, is not expected to open for service until at least the end of 2016. less

Workers celebrate the break trough of the second shaft of Gotthard Tunnel on October 15, 2010 in Sedrun, Switzerland. The world's longest tunnel, which has been under construction for 14 years, is not expected ... more

Photo: Getty Images

Workers celebrate the break trough of the second shaft of Gotthard... Photo-8566807.116216 - Houston Chronicle

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Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Workers stand in one of the Gotthard base access tunnels during the launching of the installation of railway equipment on September 2, 2011 in Erstfeld, central Switzerland. By the time it opens for service in end of 2016, the 57-kilometre (35.4-mile) long Gotthard tunnel, it will exceed Seikan rail tunnel linking the Japanese islands of Honshu and Hokkaido and the world's longest road tunnel of Laerdal in Norway, paving the way for continuous high-speed rail travel between northern and southeastern Europe. less

Workers stand in one of the Gotthard base access tunnels during the launching of the installation of railway equipment on September 2, 2011 in Erstfeld, central Switzerland. By the time it opens for service in ... more

Photo: FABRICE COFFRINI, Getty Images

Workers stand in one of the Gotthard base access tunnels during the... Photo-8566800.116216 - Houston Chronicle

Image 22 of 44

A worker waits for journalists at one of the Gotthard base access tunnels during the launching of the installation of railway equipment on September 2, 2011 in Erstfeld, central Switzerland. By the time it opens for service in end of 2016, the 57-kilometre (35.4-mile) long Gotthard tunnel, it will exceed Seikan rail tunnel linking the Japanese islands of Honshu and Hokkaido and the world's longest road tunnel of Laerdal in Norway, paving the way for continuous high-speed rail travel between northern and southeastern Europe. less

A worker waits for journalists at one of the Gotthard base access tunnels during the launching of the installation of railway equipment on September 2, 2011 in Erstfeld, central Switzerland. By the time it ... more

Photo: FABRICE COFFRINI, Getty Images

A worker waits for journalists at one of the Gotthard base access... Photo-8566804.116216 - Houston Chronicle

Image 23 of 44

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

The Gotthard Sud Infocentre visitor centre is part of the overall project for the new Alpine AlpTransit railway tunnel, the large-scale project now in progress and aimed at the modernisation of public transportation infrastructures. less

The Gotthard Sud Infocentre visitor centre is part of the overall project for the new Alpine AlpTransit railway tunnel, the large-scale project now in progress and aimed at the modernisation of public ... more

Photo: Mauro Rinaldi, Getty Images

The Gotthard Sud Infocentre visitor centre is part of the overall... Photo-8566774.116216 - Houston Chronicle

Image 37 of 44

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway tunnel in the world. The project is scheduled for completion by 2016. less

Gotthard Base Tunnel work continues on November 11, 2011 in Pollegio, Switzerland. The Gotthard Base Tunnel is a railway tunnel that will run for 54km through the Swiss Alps, making it the longest railway ... more

The Gotthard Sud Infocentre visitor centre is part of the overall project for the new Alpine AlpTransit railway tunnel.

The Gotthard Sud Infocentre visitor centre is part of the overall project for the new Alpine AlpTransit railway tunnel.

Photo: Mauro Rinaldi, Getty Images

The Gotthard Sud Infocentre visitor centre is part of the overall... Photo-8566772.116216 - Houston Chronicle

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A picture taken on May 31, 2016 shows a board celebrating the world's longest train tunnel on the eve of its opening ceremony in Attinghausen near Erstfeld. The new Gotthard Base Tunnel (GBT) is set to become the world's longest railway tunnel when it opens on June 1.The 57-kilometre (35.4-mile) tunnel, which runs under the Alps, was first conceived in sketch-form in 1947 but construction began 17 years ago. / AFP / FABRICE COFFRINI (Photo credit should read FABRICE COFFRINI/AFP/Getty Images)

A picture taken on May 31, 2016 shows a board celebrating the world's longest train tunnel on the eve of its opening ceremony in Attinghausen near Erstfeld. The new Gotthard Base Tunnel (GBT) is set to become

A picture taken on May 31, 2016 shows a board celebrating the... Photo-10168116.116216 - Houston Chronicle

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Taboola Gallery Frame Item-85307.116216 - Houston Chronicle

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An Italian train makes its way at the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base Tunnel (GBT) is set to become the world's longest railway tunnel when it opens on June 1.The 57-kilometre (35.4-mile) tunnel, which runs under the Alps, was first conceived in sketch-form in 1947 but construction began 17 years ago. / AFP / FABRICE COFFRINI (Photo credit should read FABRICE COFFRINI/AFP/Getty Images)

An Italian train makes its way at the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base

An Italian train makes its way at the north entrance of the new... Photo-10168119.116216 - Houston Chronicle

Image 42 of 44

A police officer stand guards the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base Tunnel (GBT) is set to become the world's longest railway tunnel when it opens on June 1. The 57-kilometre (35.4-mile) tunnel, which runs under the Alps, was first conceived in sketch-form in 1947 but its construction only began 17 years ago. / AFP / FABRICE COFFRINI (Photo credit should read FABRICE COFFRINI/AFP/Getty Images)

A police officer stand guards the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base Tunnel

A police officer stand guards the north entrance of the new... Photo-10168117.116216 - Houston Chronicle

Image 43 of 44

A train makes its way at the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base Tunnel (GBT) is set to become the world's longest railway tunnel when it opens on June 1.The 57-kilometre (35.4-mile) tunnel, which runs under the Alps, was first conceived in sketch-form in 1947 but construction began 17 years ago. / AFP / FABRICE COFFRINI (Photo credit should read FABRICE COFFRINI/AFP/Getty Images)

A train makes its way at the north entrance of the new Gotthard Base Tunnel the world's longest train tunnel on the eve of its opening ceremony on May 31, 2016 in Erstfeld. The new Gotthard Base Tunnel (GBT)